The present invention relates to a method of feeding groups of cigarettes to a continuous wrapping line of a packing machine.
In the tobacco industry, a packing machine is employed comprising an endless conveyor belt fitted integrally with equally spaced, substantially U-shaped pockets, each for housing a respective group of cigarettes arranged in a number of layers and fed in known manner into the respective pockets through the outlets of a loading hopper associated with the belt.
Once formed, each group is normally transferred from the respective pocket on the belt to a respective seat on a first wheel of a wrapping line, along which, each group is applied with a respective inner sheet of wrapping materialxe2x80x94normally foilxe2x80x94which is folded about the group to form an inner wrapping, and with an outer sheet of wrapping material, which is folded about the group to form an outer wrapping. When the outer sheet comprises a semirigid blank, the inner sheet is applied with a respective collar prior to the respective blank.
Transferring the group from the respective pocket on the belt to a respective seat on the first wheel of the wrapping line normally poses no problems when both the pocket and the corresponding seat are moved in steps through a transfer station for transferring the group from the pocket to the seat. On the other hand, considerable difficulty is encountered when both the belt and the wrapping line are operated continuously. In which case, in fact, for the groups to be transferred correctly from the belt to the wrapping line, each pocket and corresponding seat should, theoretically, be maintained in a given position with respect to each other throughout the transfer operation.
This would best be achieved using pockets and seats capable of being oriented with respect to the belt and first wheel respectively. Whereas, however, devising a seat movable with respect to a wheel is a fairly straightforward matter, it is not quite so easy to device a pocket movable with respect to a belt. What is more, the pockets of a continuously operating belt are difficult to combine with push devices for expelling the respective groups of cigarettes from the pockets.
It is an object of the present invention to provide a method of feeding groups of cigarettes to a continuous wrapping line of a packing machine, designed to eliminate the aforementioned drawbacks.
According to the present invention, there is provided a method of feeding a group of cigarettes to a wrapping line of a cigarette packing machine; the wrapping line being operated continuously; the method comprising a transfer step to transfer said group from a pocket on a conveyor to a first seat carried by an input wheel of said wrapping line and movable with respect to the input wheel; the pocket being integral with said conveyor and being fed continuously by the conveyor along a given endless path; said input wheel rotating about a respective first axis to feed said first seat continuously through an input station of said wrapping line; and the method being characterized in that said transfer step is performed by axially transferring the group from the pocket to a second seat, which is carried by an intermediate wheel, is movable with respect to the intermediate wheel, and is fed continuously by the intermediate wheel along a portion of said path in time with said pocket; and by then orienting at least one of said first and second seats with respect to the respective wheel, so that one of said first and second seats penetrates the other for a given time at said input station.
The present invention also relates to a device for feeding groups of cigarettes to a continuous wrapping line of a packing machine.
According to the present invention, there is provided a device for feeding a group of cigarettes to a wrapping line of a packing machine; the wrapping line comprising an input station; the device comprising a conveyor moving continuously along a given endless path and which has at least one pocket integral with the conveyor; and an input wheel of said wrapping line, the input wheel having a first axis, being fitted with at least one first seat, and rotating continuously about said first axis to feed the first seat through said input station; and the device being characterized by also comprising an intermediate wheel, which has a second axis parallel to said first axis, rotates continuously about said second axis, and is fitted with at least one second seat movable with the intermediate wheel along a portion of said path in time with said pocket; and transfer means for axially transferring said group of cigarettes from said pocket to said second seat; at least one of said first and second seats being movable with respect to the respective wheel so that one of said first and second seats penetrates the other for a given time at said input station.